Industrial Drill Bits: what Claude and GPT would buy
Two AI models chose on their own, with no web access. Nobody tested these products: this is what each one says, and how to check it.
They disagree: Claude chooses Irwin and GPT chooses Norseman
In Industrial & Scientific, Claude and GPT choose the same brand in 52 of 107 categories.
Claude Opus 5.5 · October 28, 2026
Irwin Cobalt M-35 (line)
A cobalt (M35) jobber set handles stainless and tough alloys that plain HSS bits burn out on, and the cobalt runs through the whole bit, so it keeps cutting after resharpening.
Not for: Shops that mostly drill mild steel, aluminum or wood, where a plain HSS jobber set is cheaper and less brittle; also not for anyone drilling freehand with lots of side-loading, since cobalt chips more readily.
GPT 6.1 Sol · November 10, 2026
Norseman Magnum Super Premium (line)
High-speed steel construction and a 135° split point offer a versatile balance of durability, accurate starts, and performance in common metals.
Not for: Masonry, glass, or hardened steel.
Which one fits you
cordless drill in the field
Milwaukee Red Helix Cobalt (line)
A cobalt line built for handheld cordless use on steel and stainless.
Not for: Machine-shop drill press or CNC work, where dedicated industrial jobbers or screw-machine bits are the better fit.
machine-shop precision and short rigid holes
Guhring (brand)
An industrial-grade maker of jobber and stub-length bits with tight tolerances, suited to drill presses and machining centers.
Not for: Casual handheld use, where the precision is wasted and breakage risk is higher.
Check before you buy
Where to find Irwin Cobalt M-35
- Lowe's
- Hanes Supply
- DK Hardware
Shops seen in search results on November 5, 2026. A shop missing here may sell it too. Nothing was checked by a person.
Brands that matter
- Chicago-Latrobe: US industrial maker of HSS and cobalt jobbers.
- Guhring: German industrial maker, strong in precision and stub-length bits.
- Irwin: Widely available cobalt and HSS index sets.
- Milwaukee: Cobalt lines aimed at cordless field use.
- YG-1: Korean industrial tooling maker with machine-shop drills.
- Nachi: Japanese maker known for consistent HSS and cobalt drills.
What to avoid
- Sets that say "titanium" without stating a steel grade; usually this is a thin coating on low-grade steel.
- Running cobalt bits at high speed without cutting fluid in stainless, which work-hardens the hole.
- Large-piece sets padded with duplicate small sizes and weak plastic cases.
Questions
Is titanium-coated better than cobalt?
No. Titanium (TiN) is a surface coating on HSS. Cobalt is alloyed through the whole bit and outlasts it in hard metals, including after resharpening.
Do I need cutting fluid?
For steel and especially stainless, yes. It controls heat, extends bit life and prevents work-hardening. Aluminum benefits too, to stop chips welding to the flutes.